Napping is a raised surface on a textile that is a result of brushing loose staple fibers out of the fabric structure.... The nap makes the fabric feel softer and traps air that serves as insulation. The nap is typically brushed in one direction on fabrics such as corduroy, velvet, velveteen, and flannel. Light reflects off the surface of the fabric according to the direction of the nap and produces unique aesthetic qualities on pile-weave fabrics. This aspect is important in garment construction, because if the garment pattern pieces are not laid out correctly, the end product will appear to be constructed out of fabrics of different colors.